[Distribution of Micro-plastics in the Soil Covered by Different Vegetation in Yellow River Delta Wetland]

Micro-plastics (MPs) pollution has been a hotspot in soil environment. To explore the correlation of the vegetation cover and the distribution of MPs in Yellow River Delta wetland, the characters of MPs in the soil sampled at 16 sites where reed (Phragmites communis, a low-salt dominant species) and Suaeda salsa (a high-salt dominant species) covered were investigated. The abundance of MPs here ranged to 80-4640 n·kg^-1, and the particle size ranged to 13 μm-5 mm. The main components of MPs with large size were polyethylene (PE), polyethylene terephthalate (PET) and polystyrene (PS), and the content of PET ranged to 0.22-1.16 μg·kg^-1. The barrier effect of reed on MPs was higher than that of Suaeda salsa. The average abundance of MPs and PET contents at the sites where reed covered were 1423 n·kg^-1 and 0.62 μg·kg^-1, and they mainly consisted of small particles with a size less than 50 μm. The average abundance of MPs and PET contents at the site Suaeda salsa covered were 584 n·kg^-1 and 0.33 μg·kg^-1, and they mainly consisted of fragments and fibers with a size ranged to 100-1000 μm. The abundance of MPs in the soil was significantly correlated with the growth statues of the vegetations (P=0.001). Therefore, the distribution of MPs in the soil in the same area covered by different vegetation might be spatial different.